1. Field of the Invention
The present invention is directed generally to a compact engine-generator (or alternator) combination, and specifically to a more compact engine-generator for use with unmanned submersibles (hereinafter called Unmanned Undersea Vehicles or UUVs).
2. Description of the Prior Art
An Undermanned Undersea Vehicle (UUV), which operates independent of air, must use thermal engines with air-independent fuels, or use electric power with energy delivered via primary batteries, secondary batteries, fuel cells, etc. The range of the UUVs can be significantly increased if an air breathing engine is used to recharge the batteries. This technique has not yet been accepted in UUVs since the diesel engine and generator occupy a large amount of space and weight; thereby, leaving little allocation for fuel storage and batteries. This technique is also not acceptable due in part to acoustic signature considerations. If a quiet, compact air breathing generator could be constructed, then this type of propulsion system would be of greater benefit.
Various engine types are commonly-available, such as a spark ignition combustion engine, a compression ignition internal combustion engine and an external combustion engine. These engines can be powered by either a monopropellant or bipropellant fuel/oxidizer energy source.
U.S. Pat. No. 5,343,704 to Kanzaki et al. discloses a double-headed and swash plate type engine which includes double headed pistons defining front spaces and rear spaces and anchored to the swash plate by shoes. Hence, the reciprocal movement of the double-headed pistons, due to the expansion and compression of an operating gas in the front and rear spaces, is directly converted into the rotary movement of the swash plate.
U.S. Pat. No. 4,960,082 to Sullivan et al. discloses a bent axis rotary piston engine with the capability of dual output power, improved cooling and gas flow through the engine, as well as supercharging and improved scavenging of the exhaust.
U.S. Pat. No. 6,390,052 to McMaster et al. discloses a wobble plate engine having a wobble plate that rolls against truncated cone portions of a housing and has an inner extremity rotatably supported by an axially inclined annular bearing on a spherical member of the wobble plate assembly so as to rotate a shaft during the wobbling motion.
U.S. Pat. No. 7,334,513 to Belser discloses an axial piston machine having a swash plate and a control piston which contacts the swash plate by way of a side block which is partially received by the swash plate or the control piston.
U.S. Pat. No. 6,968,751 to Shulenberger et al. discloses a system and method for converting reciprocal linear motion of one or more pistons into rotary motion of an output power shaft whose rotational axis is parallel to the motions of the pistons, or conversely rotary motion of a similarly configured input shaft into reciprocal linear motion of one or more pistons.
U.S. Pat. No. 6,174,139 to Stolzer discloses an axial piston machine which includes a cylinder block having cylinder bores in which pistons are movably guided, with the pistons being supported on an inclined or wobble plate in order to perform a lifting movement.
U.S. Patent Publication No. 2008/0271715 to duPont discloses an internal combustion two-stroke barrel engine including a power output shaft configured to rotate an even number of cylinders around the output shaft, where each cylinder includes opposing first and second power pistons configured to reciprocate within their respective power cylinder, and a pair of non-rotating wobble plates opposed and hingedly-connected to the power pistons.
U.S. Pat. No. 6,236,123 to Pinkerton discloses an electrical generator having at least one rotating ring of field magnets which produce a circular array of magnetic fields, and a ring of generator output coils which are in the magnetic fields. Pinkerton's machine is shaft driven, much like a conventional generator. Pinkerton does not disclose a piston engine with a rotating block. Specifically, Pinkerton discloses that a motor rotates a shaft, an optional flywheel, and a generator magnet assembly. Also, Pinkerton describes an ability to move the coils via an actuator to change voltage.
U.S. Pat. No. 7,400,069 to Kundel discloses a generator for producing electric power including a drive mechanism (such as a drive motor) having a rotor supported for rotation about an axis, first and second generator magnets to produce a magnetic field whose flux extends between reference poles of the magnets, plus a stator with an electrical conductor winding located adjacent to the magnets.